private void btnAddCustomer_Click(object sender, EventArgs e)
{
Customer customer = new Customer();
customer.firstName = tbFirstName.Text;
customer.lastName = tbLastName.Text;
customer.gender = cbGende.Text;
customer.phoneNumber = tbPhone.Text;
customer.address = tbAddress.Text;
customer.username = tbUsername.Text;
customer.password = tbPassword.Text;
CustomerBLL.AddCus(customer);
this.Close();
}